This nonprovisional application claims priority under 35 U.S.C. xc2xa7 119(a) on patent application Ser. No. 2001-333286 filed in Japan on Oct. 30, 2001, the entirety of which is hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a personal watercraft which includes a saddle ride type seat at a roughly central portion of a watercraft body. An engine is mounted on the lower side of the seat and is directed in the front-rear direction of the watercraft body. Furthermore, intake pipes are in communication with a plurality of cylinders provided in the engine, respectively. Each of the intake pipes extend from a side surface of the engine.
2. Description of Background Art
A personal watercraft is disclosed, for example, in Japanese Patent Laid-open No. Hei 8-48287 entitled xe2x80x9cPERSONAL PLANING WATERCRAFTxe2x80x9d. FIG. 1 of the above publication has been reproduced as FIG. 13 of the present specification. It should be noted that the reference numerals have been re-assigned to avoid confusion with FIGS. 1-12 of the present invention.
FIG. 13 is a sectional view of a personal watercraft according to the background art. The personal watercraft 100 has a structure in which left and right side walls 102 and 103 are provided at a roughly central portion of a deck 101. A saddle ride type seat 104 is provided at the upper ends of the left and right side walls 102 and 103. An engine 105 is provided on the lower side of the seat 104 and is directed in the front-rear direction of a watercraft body 106. Cylinders 105a of the engine 105 are inclined to the right side, to open a large space 107 on the left side of the engine 105. Furthermore, intake system equipment 108 is provided in the left-side space 107, whereby the intake system equipment 108 is prevented from projecting a large amount to the left side from the center 106a of the watercraft body 106.
With the intake system equipment 108 prevented from projecting a large amount to the left side from the center 106a of the watercraft body 106, the spacing between the left and right side walls 102 and 103 of the deck 101 can be suppressed to a minimum. Therefore, when the driver sits astride the saddle ride type seat 104 and put his feet on foot rest portions 101a, 101a of the deck 101, the driver can maintain a natural posture.
Incidentally, the intake system equipment 108 has a structure in which an intake silencer 108b is in communication with the cylinders 105a through air funnels 108a. An intake pipe 108c is in communication with the intake silencer 108b. 
According to the intake system equipment 108, air sucked into the intake pipe 108c through a suction port 108d of the intake pipe 108c can be led into the intake silencer 108b. The air led into the intake silencer 108b can be introduced into the cylinders 105a through the air funnels 108a. 
The engine 105 mounted on the personal watercraft 100 in some cases has a structure in which the air funnels 108a are set to have a certain length for efficient intake of air into the cylinders 105a. In this case, the air funnels 108a project a large amount to the left side from the center 106a of the watercraft body 106. In order to contain the projecting air funnels 108a in the inside of the left side wall 102, the left side wall 102 must project a large amount from the center 106a of the watercraft body 106. Therefore, when the driver sits astride the saddle ride type seat 104, a foot portion of the driver interferes with the left side wall 102, and the driver cannot sit astride the seat 104 in a natural posture.
In addition, sea water or water may penetrate into the watercraft body during an operation of the personal watercraft. Once sea water or water has penetrated into the watercraft body, the sea water or water may penetrate into the cylinders 105a through the air funnels 108a. Therefore, it has been desired to put into practical use a personal watercraft 100 which can prevent sea water or water from penetrating into the cylinders 105a, even if sea water or water penetrates into the watercraft body 106.
Accordingly, it is an object of the present invention to provide a personal watercraft which can secure comparative long air funnels in the condition where the spacing between left and right side walls of the watercraft body is suppressed to be small, and which can prevent sea water or water from penetrating into an engine even if sea water or water should have penetrated into the watercraft body.
In order to solve the above-mentioned problems, a first aspect of the present invention is directed to a personal watercraft including a saddle ride type seat at a roughly central portion of a watercraft body. Cover form side walls extend downwards from left and right lower edges of the seat. An engine is mounted on the lower side of the seat with the axis of a crankshaft thereof directed in the front-rear direction of the watercraft body. A plurality of cylinders is provided in the engine. The cylinders are arranged in the front rear direction of the watercraft body. Intake pipes are in communication with the cylinders, respectively. Each of the intake pipes extend from a side surface of the engine, wherein each of the intake pipes is bent along the side wall on the lower side of the seat.
With the intake pipes bent along the side wall on the lower side of the seat, the intake pipes can extend upwards a large amount without projecting the side wall on the lower side of the seat toward the outside. Accordingly, the spacing between the left and right side walls on the lower side of the seat can be suppressed to a minimum. Therefore, the driver can sit astride the saddle ride type seat in a natural posture.
In addition, since the intake pipes can extend a large amount upwards, the inlets of the intake pipes can be disposed at high positions. Accordingly, sea water or water can be prevented from reaching the inlets of the intake pipes, even if sea water or water penetrates into the watercraft body. Therefore, it is possible to prevent sea water or water from penetrating into the intake pipes through the inlets of the intake pipes.
According to a second aspect of the present invention, inlets of the intake pipes are arranged in a zigzag manner such that the inlets are arranged densely. The intake pipes are surrounded by an air box disposed between the engine and the side wall.
With the inlets of the intake pipes arranged in a zigzag manner, the inlets of the intake pipes can be arranged densely with respect to the front-rear direction of the watercraft body. Therefore, the air box can be made compact, so that the air box can be disposed at a desired position in the watercraft body even where the intake pipes are extended a large amount upwards. Therefore, the spacing between the left and right side walls on the lower side of the seat can be suppressed to a minimum, so that the driver can sit astride the saddle ride type seat in a natural posture.
According to a third aspect of the present invention, the intake pipes extend upwards.
With each of the intake pipes extending upwards, the inlets of the intake pipes can be disposed at high positions. Accordingly, it can be ensured that sea water or water does not easily reach the inlets of the intake pipes, even if sea water or water penetrates into the watercraft body.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.